1729561 has 4 divisors (see below), whose sum is σ = 1733392. Its totient is φ = 1725732.

The previous prime is 1729543. The next prime is 1729591. The reversal of 1729561 is 1659271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1659271 = 53 ⋅31307.

It is a cyclic number.

It is not a de Polignac number, because 1729561 - 2⁷ = 1729433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1729591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1131 + ... + 2176.

It is an arithmetic number, because the mean of its divisors is an integer number (433348).

2^1729561 is an apocalyptic number.

It is an amenable number.

1729561 is a deficient number, since it is larger than the sum of its proper divisors (3831).

1729561 is an equidigital number, since it uses as much as digits as its factorization.

1729561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3830.

The product of its digits is 3780, while the sum is 31.

The square root of 1729561 is about 1315.1277504486. The cubic root of 1729561 is about 120.0361233840.

It can be divided in two parts, 1729 and 561, that multiplied together give a palindrome (969969).

The spelling of 1729561 in words is "one million, seven hundred twenty-nine thousand, five hundred sixty-one".